The first thing that would happen would be a diplomatic shitstorm as other countries start to wonder where their citizens and diplomatic staff have gone.
Orphan City.
We’d be left without a president!
(ducks and runs)
Ah, there you go. It’d prove the birthers right or wrong.
That’s sort of whats been happening around here ever since the housing bubble popped. When the landscaping, roofing and construction jobs dried up they simply started leaving.
Since the OP is talking about legal immigrants, Silicon Valley would collapse. I suspect 90% of the people who work in my building were born overseas. A good chunk of computer engineering faculty at our universities would be gone, as well as a good chunk of graduate students in EE. A very large chunk of the part of my town with the most expensive houses would be deserted, as well as a very large chunk of our high school population.
And I would have to write all the papers for the conference I’m involved with by myself.
All restaurants close due to lack of staff. Ever read Kitchen Confidential?
Note that illegal immigrants have a net positive effect on things like Social Security:
Um…
If you mean “gingers” in the UK sense, this comment makes no sense. Lots of redheads are born in the US every day - with the exception of a long-dead great-grandmother all the redheads in my family were born here. And if you don’t mean it in the UK sense, what do you mean?
I don’t buy the lack of cheap produce argument. Here locally grown produce is less expensive than imported produce, not more, and given we don’t have many immigrant workers (only 64,000 NH residents are not US-born, and a fair number of those people are in tech and medical fields) up this way picking fruit & veggies you would expect the costs to be considerably higher given what everyone “knows” about the relationship between produce and immigrant workers.
My girlfriend disappears. 
Thank you for this. We don’t all work in construction, fast food joints or picking produce. Hell some of us aren’t even in scientific jobs…
I suspect he meant that in the absence of many visible minorities, more subtle differentiated people would begin to bear more of the brunt of discrimination. Obviously, native born visible minorities would still be around, but a chunk of visible minorities would be gone, so red-haired people would no doubt step up to the plate and fill the void in the discrimination industry.
I doubt it. There’s nothing culturally alien about red-haired people. Most of them are of Irish or Scots-Irish or English descent, in other words part of the majority. Real discrimination is about more than just how someone looks. I don’t think that all the anti-immigrant racists would suddenly just turn their hatred against someone else. I don’t think it works that way.
The Governors of California and Michigan would vanish.
As would Sen. John McCain.
Sure - if you look at the history of areas that were 100% white, such as Scotland, for example, discrimination was non-existant. It isn’t that sectarianism took its place, with different housing estates, unions and football teams for Catholics and Protestants.
No birthers have mentioned Obama yet?
Well, at least if this all happened magically and immigrants in the US went poof overnight we’d know for sure if Obama was really a Kenyan. So one problem put to rest. 
I don’t know if it would be sudden, but it might happen eventually. It feels good to be able to blame somebody else, somebody who is different from you, when your life isn’t going the way you’d like it to.
I’d love to answer this question, but half my family just disappeared and…<POP!>
-XT
Kal Penn and M. Night Shyamalan I believe both immigrants. I’m not positive - Kal Penn may have been born here.
And yes, there are so many immigrant Indians in comp sci…I thank you too, Voyager.